Submersible observations of deep-reef fishes of Heceta Bank, Oregon

Rock fishes, Sebastes spp. (Scorpaenidae) were the most numerous and speciose fishes seen from 64-305m depth. Dense schools of juvenile rockfishes and large yellowtail rockfish, S. flavidus, were observed only over rocky, high relief areas near the top of the bank, and highest densities of small benthic rockfishes (up to 5-10/m²) on the flanks of the bank. Observations suggest that shallow, rocky portions of Heceta Bank are a nursery area for juvenile rockfishes. Two species groups of nonschooling fishes were identified based on transects over the diverse seafloor habitats around the bank: one comprised primarily of rockfishes in shallow water on rock and cobble, and the other comprised of flatfishes, agonids, sablefish and some rockfishes in deep water over mud and cobble. Species composition of fishes observed from submersible dives differed from species composition of fishes taken from trawl catches. -from Authors